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<title>RSM—Resume from System Management Mode </title></head>
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<h1>RSM—Resume from System Management Mode</h1>
<table>
<tr>
<th>Opcode*</th>
<th>Instruction</th>
<th>Op/En</th>
<th>64-Bit Mode</th>
<th>Compat/Leg Mode</th>
<th>Description</th></tr>
<tr>
<td>0F AA</td>
<td>RSM</td>
<td>NP</td>
<td>Valid</td>
<td>Valid</td>
<td>Resume operation of interrupted program.</td></tr></table>
<h3>Instruction Operand Encoding</h3>
<table>
<tr>
<td>Op/En</td>
<td>Operand 1</td>
<td>Operand 2</td>
<td>Operand 3</td>
<td>Operand 4</td></tr>
<tr>
<td>NP</td>
<td>NA</td>
<td>NA</td>
<td>NA</td>
<td>NA</td></tr></table>
<h2>Description</h2>
<p>Returns program control from system management mode (SMM) to the application program or operating-system procedure that was interrupted when the processor received an SMM interrupt. The processor’s state is restored from the dump created upon entering SMM. If the processor detects invalid state information during state restora-tion, it enters the shutdown state. The following invalid information can cause a shutdown:</p>
<p>The contents of the model-specific registers are not affected by a return from SMM.</p>
<p>The SMM state map used by RSM supports resuming processor context for non-64-bit modes and 64-bit mode.</p>
<p>See Chapter 34, “System Management Mode,” in the <em>Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3C</em>, for more information about SMM and the behavior of the RSM instruction.</p>
<h2>Operation</h2>
<pre>ReturnFromSMM;
IF (IA-32e mode supported) or (CPUID DisplayFamily_DisplayModel = 06H_0CH )
    THEN
         ProcessorState ← Restore(SMMDump(IA-32e SMM STATE MAP));
    Else
         ProcessorState ← Restore(SMMDump(Non-32-Bit-Mode SMM STATE MAP));
FI</pre>
<h2>Flags Affected</h2>
<p>All.</p>
<h2>Protected Mode Exceptions</h2>
<table class="exception-table">
<tr>
<td>#UD</td>
<td>
<p>If an attempt is made to execute this instruction when the processor is not in SMM.</p>
<p>If the LOCK prefix is used.</p></td></tr></table>
<h2>Real-Address Mode Exceptions</h2>
<p>Same exceptions as in protected mode.</p>
<h2>Virtual-8086 Mode Exceptions</h2>
<p>Same exceptions as in protected mode.</p>
<h2>Compatibility Mode Exceptions</h2>
<p>Same exceptions as in protected mode.</p>
<h2>64-Bit Mode Exceptions</h2>
<p>Same exceptions as in protected mode.</p></body></html>